Might be difference in local terminology, but by "test plans" I mean spreadsheets, typically in Excel (sometimes printed and bound), that described step by step

Might be difference in local terminology, but by "test plans" I mean spreadsheets, typically in Excel (sometimes printed and bound), that described step by step every test for manual tester to follow. And that's how a lot of testing is done in various companies, especially where manual testing is still common, at least in Poland.